CREATE TABLE numbers
(number int)

INSERT INTO numbers
VALUES (10)
INSERT INTO numbers
VALUES (12)
INSERT INTO numbers
VALUES (16)
INSERT INTO numbers
VALUES (18)
INSERT INTO numbers
VALUES (19)
INSERT INTO numbers
VALUES (27)
INSERT INTO numbers
VALUES (29)

[sourcecode language="sql" padlinenumbers="true"]
SELECT MAX(number)
FROM numbers
WHERE number < (SELECT max(number) FROM numbers)